Is SLC2A1 p.Phe447= (c.1341C>T) pathogenic?

SLC2A1 p.Phe447= (c.1341C>T) is classified Likely benign in SLC2A1 (ClinVar, Single submitter, 1 submitter; last evaluated 2026-01-05). Very rare (popmax 0.00333%, amr); Associated with GLUT1 deficiency syndrome 1, autosomal recessive.

What condition is associated with SLC2A1 p.Phe447= (c.1341C>T)?

SLC2A1 p.Phe447= (c.1341C>T) is associated with GLUT1 deficiency syndrome 1, autosomal recessive (ClinVar).

How common is SLC2A1 p.Phe447= (c.1341C>T) in the general population?

SLC2A1 p.Phe447= (c.1341C>T) is very rare (popmax 0.00333%, amr) (gnomAD).

SLC2A1 p.Phe447=

c.1341C>T · rs977758531 · VCV1101674

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00333%, amr)

Conditions

GLUT1 deficiency syndrome 1, autosomal recessive

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.1	GERP -0.16, phastCons 1
Overall
CADD	9.227	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00333% Admixed American · 2/60,016 alleles

Filtering AF 0.00172% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00149%

Overall 0.00204% 33/1,614,072 alleles · very rare

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.00333%	30,008
Remaining individualsnot grpmax-eligible	0.0032%	31,245
European (non-Finnish)	0.00246%	40,690

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: SLC2A1
Protein: p.Phe447=
Coding: c.1341C>T
MANE Select: NM_006516
dbSNP: rs977758531
Type: single nucleotide variant
Location: chr1:42927179 (GRCh38)
Gene constraint: LOEUF 0.139 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 90.30 · 5 PDB
Residue 447: an α-helix

Full SLC2A1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

GLUT1 deficiency syndrome 1, autosomal recessive — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

SLC2A1 c.1279-2A>G Likely pathogenic ★★ same condition
SLC2A1 c.-107G>A Pathogenic/Likely pathogenic ★★ same condition
SLC2A1 p.Asn34Asp Pathogenic/Likely pathogenic ★★ same condition
SLC2A1 p.Gln200Ter Pathogenic/Likely pathogenic ★★ same condition
SLC2A1 p.Leu215Phe Likely pathogenic ★★ same condition
SLC2A1 p.Met420Thr Pathogenic/Likely pathogenic ★★ ⚠ same condition
SLC2A1 p.Met96Val Pathogenic/Likely pathogenic ★★ ⚠ same condition
SLC2A1 p.Pro211Ser Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/slc2a1-p-phe447 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown